CN117321726A

CN117321726A - Focused ion beam device

Info

Publication number: CN117321726A
Application number: CN202280035655.5A
Authority: CN
Inventors: 水村通伸
Original assignee: V Technology Co Ltd
Current assignee: V Technology Co Ltd
Priority date: 2021-07-19
Filing date: 2022-03-10
Publication date: 2023-12-29
Also published as: KR20240037199A; JP2023014664A; WO2023002674A1; TW202305858A

Abstract

The focused ion beam device is provided with: a beam emitting unit that includes a focused ion beam optical system that adjusts an ion beam extracted from an ion source into an internal space to emit the ion beam; and an opening portion that communicates with the internal space and is capable of passing the ion beam emitted from the beam emitting portion to irradiate the target substrate with the ion beam, wherein the internal space is evacuated, and the focusing ion beam device includes a movable sealing valve capable of opening and closing the opening portion.

Description

Focused ion beam device

Technical Field

The present invention relates to focused ion beam devices.

Background

A charged particle beam lithography apparatus is known (for example, see patent document 1). The charged particle beam lithography apparatus includes a beam irradiation apparatus and a vacuum encapsulation apparatus. The beam irradiation device maintains the internal space in a high vacuum state, and a front end opening is provided at the front end of the beam emission side. The vacuum packaging device is provided so as to surround the front end opening of the beam irradiation device, and has a function of locally setting the space near the front end opening to a vacuum state. The vacuum packaging device is capable of keeping a space between the front end portion of the beam irradiation device and the surface to be processed in a high vacuum state by narrowing a gap between the vacuum packaging device and the surface to be processed as much as possible by approaching the surface to be processed (surface) of the semiconductor wafer.

In this charged particle beam lithography apparatus, in order to perform various adjustments of the position and beam of the charged particle beam, the following detection operation is required. That is, the charged particle beam emitted through the front end opening is irradiated to the fiducial mark formed on the alignment pad disposed on the periphery of the semiconductor wafer. Based on information obtained by irradiation of the reference mark with the charged particle beam, adjustment of the position of the charged particle beam, the shape of the beam, and the like is performed in the beam irradiation apparatus. The reason why the inspection operation is performed using the reference mark formed on the adjustment pad is that if the charged particle beam is directly irradiated to the semiconductor wafer, the semiconductor wafer is damaged. Such inspection operation is performed every time a semiconductor wafer is replaced.

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open No. 59-90926

Disclosure of Invention

Problems to be solved by the invention

In the charged particle beam lithography apparatus described above, each time the position of the charged particle beam, the beam shape, and the like are adjusted, the charged particle beam lithography apparatus needs to be relatively moved so as to be disposed above the reference mark of the adjustment pad, and thus there is a problem that the tact time (tact time) during the processing of the semiconductor wafer increases.

Further, in the charged particle beam lithography apparatus described above, there is a problem that the space between the front end portion of the beam irradiation apparatus and the surface to be processed cannot be kept in a high vacuum state when the vacuum encapsulation apparatus is away from the surface to be processed of the semiconductor wafer. In general, the replacement of the semiconductor wafer is performed in a state in which the charged particle beam lithography apparatus is moved to a standby position from the semiconductor wafer. Therefore, each time the semiconductor wafer is replaced, the inside of the beam irradiation device is temporarily brought into a low vacuum state. Therefore, after the replacement of the next semiconductor wafer, the charged particle beam lithography apparatus is brought close to the semiconductor wafer, and the internal space of the beam irradiation apparatus is adjusted to a high vacuum state while the vacuum packaging apparatus is operated. Therefore, the moving work of the charged particle beam lithography apparatus and the time for adjusting the pressure are required. Accordingly, such a charged particle beam lithography apparatus has a problem that the takt time during processing of a semiconductor wafer increases.

The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a focused ion beam apparatus capable of shortening a tact time without damaging a target substrate itself during ion beam adjustment.

Means for solving the problems

In order to solve the above problems and achieve the object, a focused ion beam device according to an aspect of the present invention includes: a beam emitting unit that includes a focused ion beam optical system that adjusts an ion beam extracted from an ion source into an internal space to emit the ion beam; and an opening portion that communicates with the internal space and is capable of passing the ion beam emitted from the beam emitting portion to irradiate the target substrate with the ion beam, wherein the internal space is evacuated, and wherein the focusing ion beam device includes a movable sealing valve capable of opening and closing the opening portion.

In the above aspect, it is preferable that a secondary charged particle detector for detecting secondary charged particles is provided in the internal space, and an adjustment reference pattern is arranged at a position irradiated with the ion beam when the opening is closed in the movable seal valve.

As the above, it is preferable that a current meter is connected to the adjustment reference pattern.

As the above, it is preferable that the beam emitting unit includes: a focused ion beam column in which the focused ion beam optical system is incorporated; and a head portion including a differential exhaust portion disposed at an end portion of the focused ion beam column on an emission side.

In the above aspect, the internal space is preferably a space formed in communication between the focused ion beam column and the head, and the opening is preferably formed in the head.

In the above aspect, the internal space is preferably a space formed inside the focused ion beam column, and the opening is preferably formed at an end of the focused ion beam column on an emission side.

As the above, it is preferable that the movable sealing valve is reciprocally driven between a position where the opening is closed and a standby position where the internal space is not irradiated with the ion beam.

As the above, it is preferable that the adjustment reference pattern is a metal mesh.

As the above, it is preferable that the ammeter be Pi Anji.

Effects of the invention

According to the focused ion beam apparatus of the present invention, there is an effect of shortening the tact time required for processing a substrate to be processed using a focused ion beam.

Drawings

Fig. 1 is a schematic configuration diagram of a focused ion beam apparatus according to a first embodiment of the present invention, showing a state in which a movable sealing valve is opened.

Fig. 2 is a schematic configuration diagram of a focused ion beam apparatus according to a first embodiment of the present invention, showing a state in which a movable sealing valve is closed.

Fig. 3 is a perspective view showing a main part of a tip portion of a movable seal valve of a focused ion beam apparatus according to a first embodiment of the present invention.

Fig. 4 is a plan view of a metal mesh (reference mark for adjustment) provided in a movable seal valve of a focused ion beam apparatus according to a first embodiment of the present invention.

Fig. 5 is a schematic configuration diagram of a focused ion beam apparatus according to a second embodiment of the present invention, showing a state in which a movable sealing valve is opened.

Fig. 6 is a schematic configuration diagram of a focused ion beam apparatus according to a second embodiment of the present invention, showing a state in which a movable sealing valve is closed.

Detailed Description

Details of a focused ion beam device according to an embodiment of the present invention will be described below with reference to the drawings. It should be noted that the drawings are schematic, and the number of the respective members, the sizes of the respective members, the proportion of the sizes, the shapes, and the like are different from those of the actual ones. The drawings also include portions having different dimensional relationships, proportions, and shapes.

[ first embodiment ] (Structure of focused ion Beam device)

The focused ion beam device according to the first embodiment of the present invention can be used as a photomask correction device for use in manufacturing thin displays (FPD: flat Panel Display) such as liquid crystal displays (LCD: liquid Crystal Display) and organic EL displays (OLED: organic Electroluminescence Display).

As shown in fig. 1, the focused ion beam device 1 of the present embodiment includes a substrate support table 2, a focused ion beam column 3, a head 4, a differential exhaust unit 5, a secondary charged particle detector 6, a movable sealing valve 7, a galvanometer 8, a valve driving unit 9, and a control unit 10. The focused ion beam column 3 and the head 4 constitute a beam emitting section 11.

The substrate support table 2 supports the substrate 12 to be processed in a mounted state. In the present embodiment, a large photomask is used as the target substrate 12. The substrate support table 2 is movable relative to the beam emitting unit 11 in the X-Y direction. The substrate support table 2 can also be moved relative to the beam emitting unit 11 in the Z direction.

(focused ion Beam column)

The focused ion beam column 3 includes a barrel 13, and a liquid metal ion source 14 and a focused ion beam optical system 15 are provided in a barrel internal space 13A in the barrel 13. A vacuum pump (not shown) (e.g., an ion pump) is connected to the upper portion of the lens barrel 13 via a connecting tube 13B. A barrel front end opening 13C through which the ion beam IB can pass is formed at a front end (lower end) of the barrel 13.

The liquid metal ion source 14 includes, for example, gallium (Ga) as a liquid metal. In the liquid metal ion source 14, the liquid metal is ionized by field emission to release gallium ions (ga+) from the front end.

The focused ion beam optical system 15 includes a condenser lens 16, an aperture (aperture) 17, an astigmatism correction astigmatic device 18, a blanking device (blanking device) 19, a blanking aperture 20, a deflector 21, and an objective lens 22. In the present embodiment, the condenser lens 16, the astigmatism correction astigmatic device 18, the blanking device 19, the deflector 21, and the objective lens 22 are controlled based on a control signal from the control unit 10.

The condenser lens 16 is an electrostatic lens. Gallium ions (ga+) emitted from the liquid metal ion source 14 are accelerated by an acceleration voltage (a part of which is an ion overvoltage) by an extraction electrode (not shown) on the most upstream side of the condenser lens 16 to become an ion beam IB.

The astigmatism correction stigmator 18 is constituted by, for example, eight polarization electrodes, not shown. In the astigmatism correction stigmator 18, the magnitude of the voltage values of the eight polarization electrodes is changed based on a control signal from the control unit 10, whereby the axial offset and beam shape of the ion beam IB can be changed.

The blanking unit 19 has the following functions: by applying a blanking voltage based on a control signal from the control section 10, the ion beam IB is deflected to be directed to the light shielding section (region where the aperture is not formed) of the blanking diaphragm 20 so that the ion beam IB does not face the substrate 12 to be processed.

The deflector 21 is capable of deflecting the ion beam IB to scan in the X-Y direction. The objective lens 22 is an electrostatic lens, and has the following functions: based on a control signal from the control section 10, focusing is performed so that the ion beam IB is focused on the surface of the substrate 12 to be processed.

(head)

As shown in fig. 1, the head 4 is a hollow body having a substantially disk shape and disposed so that the central axis coincides with the central axis of the lens barrel 13. The head 4 is composed of a disk-shaped upper body 41, a disk-shaped lower body 42, and a groove 43, which are formed by cutting an upper part of a cone, and a head internal space 4A is formed therein. The head internal space 4A communicates with the barrel internal space 13A in the barrel 13 of the focused ion beam column 3 to form an internal space of the beam emitting portion 11. The internal space is evacuated to a predetermined vacuum degree by a vacuum pump (not shown) connected via a connecting tube 13B at the upper part of the lens barrel 13.

A cylindrical body coupling port 41A is formed in the center of the upper body 41, and penetrates in the rotation axis direction. The lower body 42 has a lower body opening 42A formed in the center. A head tip opening 43A is formed in the center of the channel plate 43. The head tip opening 43A is an opening through which the ion beam IB passes to irradiate the target substrate 12 with the beam. The front end portions of the focused ion beam columns 3 are coupled in a penetrating state at the column coupling ports 41A. The differential exhaust portion 5 is provided on the lower surface of the lower body 42 so as to surround the head tip opening 43A.

(differential exhaust section)

The differential exhaust unit 5 is configured using a lower body 42 and a groove forming plate 43. The lower surface 43B of the groove forming plate 43 is formed with, for example, three annular grooves 44, 45, 46 arranged concentrically at a predetermined distance in the radial direction so as to surround the head tip opening 43A.

Communication grooves 47, 48, 49, 50 are formed in the lower surface of the lower body 42 to appropriately communicate with the annular grooves 44, 45, 46. These communication grooves 47, 48, 49, 50 are connected to a vacuum pump, not shown, in a path, not shown.

In the present embodiment, the suction/exhaust performance of the annular grooves 44, 45, 46 is set to gradually rise from the outer annular groove 46 toward the inner annular groove 44, so as to perform differential exhaust. That is, the annular grooves 44, 45, 46 are set to be gradually set to a low pressure as going from the outermost annular groove 46 to the innermost annular groove 44.

(secondary charged particle Detector)

The head 4 is provided with a secondary charged particle detector 6. The front end side of the secondary charged particle detector 6 is disposed in the head internal space 4A. The secondary charged particle detector 6 is connected to the control unit 10, and can output detected information to the control unit 10.

In the present embodiment, the secondary charged particle detector 6 is constituted by a scintillator. The front end portion of the secondary charged particle detector 6 is disposed laterally toward the head front end opening 43A so as not to directly contact the ion beam IB. A photomultiplier tube (not shown) for amplifying light generated by the secondary charged particle detector 6 is connected to the secondary charged particle detector 6.

The secondary charged particle detector 6 is configured to capture secondary charged particles emitted from a metal mesh 74 as an adjustment reference pattern provided on a movable seal valve 7 described later by irradiation with an ion beam IB, and to obtain surface information of the metal mesh 74. The position and the beam of the ion beam IB can be variously adjusted based on the surface information of the metal mesh 74 obtained from the secondary charged particle detector 6.

(Movable sealing valve)

As shown in fig. 1 and 2, the movable seal valve 7 has a function of opening and closing the head tip opening 43A from the inside of the head 4. As shown in fig. 1 to 3, the movable seal valve 7 includes a stem 71, a valve body 72, a vacuum pad 73, and a metal mesh (adjustment reference pattern) 74.

The rod portion 71 penetrates the head portion 4 and is configured to be capable of reciprocating in the axial direction while maintaining the vacuum degree of the head internal space 4A. The stem 71 is driven by a valve driving portion 9 provided outside the head 4. The valve driving section 9 drives the lever section 71 based on a control signal from the control section 10. In the present embodiment, for example, an air actuator is used as the valve driving unit 9.

As shown in fig. 3, the valve main body 72 is provided at the front end portion of the stem portion 71. A vacuum pad 73 is provided on the lower surface of the valve main body 72. The vacuum pad 73 is formed of, for example, a fluororesin. The vacuum pad 73 moves between a position (standby position) where the head front end opening 43A shown in fig. 1 is opened without interfering with the ion beam IB and a position where the head front end opening 43A shown in fig. 2 is closed, along with the movement of the rod portion 71.

The metal mesh 74 moves between a position (standby position) shown in fig. 1 where the metal mesh does not interfere with the ion beam IB and a position shown in fig. 2 where the ion beam IB is irradiated, with the movement of the rod 71. As shown in fig. 4, the metal mesh 74 includes a circular frame 74A and a circular metal mesh body 74B fixed to the frame 74A. The metal mesh 74 may be detachably supported by the valve body 72. The valve body 72 may be detachably supported by the stem 71. The metal mesh body 74B may be made of, for example, molybdenum (Mo), tin (Sn), gold (Au), or the like.

As described above, in the focused ion beam device 1, the metal mesh 74 emits the secondary charged particles by the irradiation of the ion beam IB, and the secondary charged particle detector 6 captures the secondary charged particles. The control unit 10 can perform various adjustments of the irradiation position of the ion beam IB and the beam by supplying surface information of the metal mesh 74 from the secondary charged particle detector 6.

In the present embodiment, the ammeter 8 is connected to the metal mesh 74 of the movable seal valve 7 via the rod portion 71. In the present embodiment, the ammeter 8 is a picoammeter that measures a minute direct current. The movable sealing valve 7 can detect the current value of the ion beam IB by the galvanometer 8. Therefore, the control unit 10 can adjust the beam current of the ion beam IB based on the current value detected by the galvanometer 8.

(action and action of focused ion Beam device)

As shown in fig. 1, when processing such as correction of a mask pattern is performed by irradiating the ion beam IB onto the target substrate 12 using the focused ion beam apparatus 1, differential exhaust is performed while a predetermined narrow gap is maintained between the lower surface of the groove forming plate 43 constituting the differential exhaust section 5 and the target substrate 12.

At this time, the internal space formed by the barrel internal space 13A and the head internal space 4A is in a state of being evacuated at a predetermined vacuum degree by a vacuum pump, not shown, connected via a connecting tube 13B at the upper part of the barrel 13.

As shown in fig. 1, the movable sealing valve 7 has a valve main body 72 disposed at a standby position where the valve main body does not interfere with the ion beam IB. That is, since the vacuum pad 73 and the metal mesh 74 are disposed at the standby position, the head tip opening 43A is opened, and the ion beam IB is not irradiated to the metal mesh 74.

In this state, an ion beam IB is generated from the focused ion beam column 3, and the ion beam IB is irradiated onto the target substrate 12 to perform processing such as correction.

Next, in the focused ion beam apparatus 1, when various adjustments of the position and beam of the ion beam IB are performed, as shown in fig. 2, the movable sealing valve 7 is operated to set the vacuum pad 73 in a state of closing the head tip opening 42A. At this time, the internal space (the barrel internal space 13A and the head internal space 4A) is blocked from the external space by the movable seal valve 7, and thus, the internal pressure is maintained.

Next, as shown in fig. 2, the ion beam IB is raster scanned against the metal mesh 74 of the movable seal valve 7. Secondary charged particles are generated in association with the irradiation of the ion beam IB. The secondary charged particle detector 6 captures the secondary charged particles and outputs a detection signal to the control unit 10. When the irradiation position of the ion beam IB is matched with the detection signal, the SIM (Scanning Ion Microscope) image of the metal mesh 74 can be observed. The position adjustment, the output adjustment, the focus adjustment, the axis adjustment, the astigmatism correction, and other various adjustments of the ion beam IB can be performed while observing the SIM image, and the ion beam IB can be set to an optimal state.

As described above, after various adjustments of the ion beam IB, the lens voltage of the objective lens 22 may be adjusted so that the ion beam IB is focused on a position on the surface of the substrate 12 to be processed, which is separated from the position of the metal mesh 74 by a predetermined design value. Therefore, the processing of the target substrate 12 can be performed virtually immediately without performing focus adjustment on the surface of the target substrate 12. The beam current can be measured simultaneously by the ammeter 8 connected to the movable seal valve 7, whereby the control unit 10 can adjust the beam current of the ion beam IB.

(effects of the first embodiment)

When the focused ion beam device 1 is used to perform correction processing on a photomask serving as the target substrate 12, various adjustments of the position and beam of the ion beam IB must be performed during the operation. In order to perform accurate correction operation regardless of the size of the photomask, it is required to maintain the state of the ion beam IB properly at all times. In the focused ion beam device 1 of the present embodiment, even during the correction operation, the adjustment operation of the ion beam IB can be performed rapidly without breaking the vacuum in the internal space (the lens barrel internal space 13A and the head internal space 4A). Therefore, the tact time can be greatly shortened in the processing of the processed substrate 12.

In addition, as described above, the vacuum in the internal space (the barrel internal space 13A and the head internal space 4A) is not broken every time the adjustment operation of the ion beam IB is performed, and thus the load of a vacuum pump (not shown) connected to the connecting tube 13B can be significantly reduced.

In the focused ion beam device 1 of the present embodiment, by providing the movable sealing valve 7 in the head internal space 4A in which the secondary charged particle detector 6 is disposed, the opening and closing of the head tip opening 43A can be performed efficiently without affecting the positional relationship between the beam emitting portion 11 and the substrate 12 to be processed.

In the focused ion beam device 1 of the present embodiment, since the metal mesh 74 is set to be automatically disposed at a position where the ion beam IB can be irradiated when the movable seal valve 7 is closed, the ion beam IB can be immediately adjusted.

In the focused ion beam device 1 of the present embodiment, the irradiation of the ion beam IB onto the target substrate 12 can be avoided when detecting the secondary charged particles, and therefore the damage of the target substrate 12 by the ion beam IB can be prevented.

Incidentally, conventionally, the ion beam IB is irradiated onto the substrate 12 to be processed to detect secondary charged particles generated from the substrate 12 to be processed while performing adjustment operations such as trajectory adjustment (orientation), focus adjustment, and astigmatism correction of the ion beam IB.

As the liquid metal ion source 14, the sputtering process rate can be increased by using the ion beam IB of gallium having a large mass number, but on the other hand, there is a problem that the irradiated photomask is inevitably processed.

That is, when the focused ion beam device is used for the correction operation of the photomask, if the adjustment operation takes a long time, there is a problem that peripheral portions other than the defective portion (correction scheduled area) that do not need correction are also processed. In the above-described focused ion beam apparatus 1, the target substrate 12 is not used in the adjustment operation of the ion beam IB, and therefore the target substrate 12 is not damaged.

Second embodiment

Fig. 5 and 6 show a focused ion beam apparatus 1A according to a second embodiment of the present invention. In the description of the focused ion beam device 1A of the present embodiment, a portion different from the configuration of the first embodiment will be described, and the description will be omitted for the same configuration.

In the focused ion beam device 1A, a column inner space 13A in the column 13 constituting the focused ion beam column 3 corresponds to an inner space of the present invention. The barrel front end opening 13C corresponds to an opening to be opened and closed in the present invention. In the present embodiment, the portion corresponding to the head 4 in the first embodiment is constituted by the head plate 51 and the groove forming portion 43. The differential exhaust section 5 is configured using a head plate 51 and a groove forming plate 43.

In the present embodiment, the secondary charged particle detector 6 and the movable sealing valve 7 are disposed in the lower portion of the barrel internal space 13A of the barrel 13. The vacuum pad 73 of the movable seal valve 7 is set to open and close the barrel front end opening 13C. Other structures of the focused ion beam device 1A of the present embodiment are the same as those of the focused ion beam device 1 of the first embodiment.

The focused ion beam device 1A of the present embodiment has the same effects as those of the focused ion beam device 1 of the first embodiment. In the focused ion beam device 1A of the present embodiment, the secondary charged particle detector 6 and the movable sealing valve 7 are disposed in the barrel internal space 13A, thereby achieving a compact and lightweight device.

Other embodiments

While the embodiments of the present invention have been described above, it should be understood that the discussion and drawings that form a part of the disclosure of the embodiments are not intended to limit the invention. Various alternative implementations, examples, and application techniques will be known to those skilled in the art from this disclosure.

In the above-described embodiment, the photomask is applied as the target substrate 12, but the present invention is not limited to this, and various samples to be subjected to the process by the ion beam IB may be applied, and the present invention is not limited to the application of correction.

In the above embodiment, the air actuator is used as the valve driving portion 9, but the present invention is not limited thereto, and other actuators may be applied.

In the above-described embodiment, the metal mesh 74 is used as the reference pattern for adjustment, but the present invention is not limited thereto, and various shapes of patterns formed of various materials may be used.

In the above-described embodiment, the secondary charged particle detector 6 is applied to a scintillator, but the present invention is not limited thereto, and a mechanism capable of detecting various charged particles, electrons, and ions, such as a multichannel plate (MCP), may be used.

In the above embodiment, the picoammeter is applied as the ammeter 8, but the ammeter 8 may be omitted.

Symbol description

IB ion beam

1. 1A focusing ion beam device

2. Substrate supporting table

3. Focused ion beam column

4. Head part

4A head interior space

5. Differential exhaust unit

6. Secondary charged particle detector

7. Movable sealing valve

8. Current meter

9. Valve driving part

10. Control unit

11. Beam emitting unit

12. Substrate to be processed

13. Lens barrel

13A lens barrel inner space

13B connecting pipe

Front opening of 13C lens cone

14. Liquid metal ion source

15. Focusing ion beam optical system

16. Condensing lens

17. Aperture diaphragm

18. Astigmatic device for astigmatic correction

19. Blanking device

20. Blanking aperture

21. Deflector device

22. Objective lens

41. Upper main body

41A column body joint

42. Lower main body

42A lower body opening

43. Groove forming plate

43A head tip opening (opening capable of beam irradiation)

43B lower surface

44. 45, 46 annular groove

47. 48, 49, 50 communicating grooves

51. Head plate

71. Rod part

72. Valve body

73. Vacuum pad

74 metal mesh (reference pattern for adjustment).

Claims

1. A focused ion beam device is provided with:

a beam emitting unit that includes a focused ion beam optical system that adjusts an ion beam extracted from an ion source into an internal space to emit the ion beam; and

an opening communicating with the internal space and capable of passing the ion beam emitted from the beam emitting unit to irradiate the substrate to be processed with the ion beam,

the internal space is evacuated and the vacuum is applied,

the focused ion beam apparatus is characterized in that,

the movable sealing valve is provided to open and close the opening.

2. The focused ion beam apparatus of claim 1 wherein,

the internal space is provided with a secondary charged particle detector for detecting secondary charged particles, and an adjustment reference pattern is arranged at a position irradiated with an ion beam when the opening is closed in the movable seal valve.

3. The focused ion beam apparatus of claim 2 wherein,

a galvanometer is connected to the adjustment reference pattern.

4. The focused ion beam device according to any one of claims 1 to 3, wherein,

the beam emitting unit includes: a focused ion beam column in which the focused ion beam optical system is incorporated; and a head portion including a differential exhaust portion disposed at an end portion of the focused ion beam column on an emission side.

5. The focused ion beam apparatus of claim 4 wherein,

the inner space is a space formed in communication between the focused ion beam column and the head, and the opening is formed in the head.

6. The focused ion beam apparatus of claim 4 wherein,

the inner space is a space formed inside the focused ion beam column, and the opening is formed at an end of the focused ion beam column on an emission side.

7. The focused ion beam device according to any one of claims 1 to 3, wherein,

the movable sealing valve is reciprocally driven between a position closing the opening and a standby position in the internal space where the ion beam is not irradiated.

8. The focused ion beam apparatus of claim 2 wherein,

the reference pattern for adjustment is a metal mesh.

9. The focused ion beam apparatus of claim 3, wherein,

the current meter is Pi Anji.